David J. Margolis, MD PhD is currently an Associate Professor of Dermatology, an Associate Professor of Epidemiology in the Department of Biostatistics and Epidemiology, and a Senior Scholar (core faculty member) in the Center for Clinical Epidemiology and Biostatistics of the University of Pennsylvania. He is an established patient-oriented researcher with an extensive track record of successful research. His research record attests to his commitment to a career in patient-oriented research, which has been focused on the prevention and treatment of chronic wounds, and his desire to be a mentor. He has applied a wide variety of epidemiologic tools and patient-oriented research methods to address research issues. His immediate and long-term career goals center on his desire and intention to continue to evolve and mature as a patient-oriented researcher, teacher, and mentor. Resources available to him, on and around the Penn campus, include all of the components necessary for successful patient-oriented research and mentoring including biostatistical support, data management support, and state of the art research/clinical laboratory services. His patient-oriented NAIMS-funded research project is, after many years of delay, in its first of five years. [unreadable] Most patients with chronic wounds of the lower extremity fail to heal in a reasonable period of time. We Have hypothesized that a growth factor associated with wound healing PDGF-BB, when produced in large quantities within the wound bed due to adenovirus-mediated gene over expression by the cells of the wound bed, will dramatically enhance wound healing. This study will use a unique and innovative gene therapy approach, adenovirus-Ad5 and the PDGF-B gene, to insure delivery of a cytokine growth factor to a non-healing wound. The aim of the proposed research study is to assess whether PDGF-BB via in vivo PDGF-BB gene transduction via an intra-ulcer injection of H5.020CMVPDGF-B in patients with a chronic venous leg ulcers can induce the local acquisition of endothelial precursor cells. [unreadable] [unreadable] [unreadable]